Ramsey was substituted during the second half of Arsenal's 2-1 defeat at United and a club statement said he will be replaced by Johan Djourou in the squad for the trip to Gelsenkirchen.
The Welshman's injury could open the door for Theo Walcott to regain a starting spot after the England winger was consigned to the bench in recent weeks following an impasse on signing a new contract.
Schalke top Group B with seven points and are one ahead of Arsenal after they won 2-0 in London last month.
- Sports & Recreation
- Johan Djourou
- Theo Walcott